Semiconductor device and manufacturing method thereof

Abstract

In a method, a gate dielectric film is formed on a semiconductor substrate. A gate electrode is formed on the gate dielectric film. Impurities of a first conduction-type are introduced into a drain-layer formation region. The impurities of the first conduction-type in the drain-layer formation region are activated by performing heat treatment. Single crystals of the semiconductor substrate in a source-layer formation region are amorphized by introducing inert impurities into the source-layer formation region. Impurities of a second conduction-type is introduced into the source-layer formation region. At least an amorphous semiconductor in the source-layer formation region is brought into a single crystal semiconductor and the impurities of the second conduction-type in the source-layer formation region is activated by irradiating the semiconductor substrate with microwaves. The impurities of the second conduction-type in the source-layer formation region is shallower than the impurities of the first conduction-type in the drain-layer formation region.

The invention claimed is: 
     
       1. A method of manufacturing a semiconductor device, comprising:
 forming a gate dielectric film on a semiconductor substrate; 
 forming a gate electrode on the gate dielectric film; 
 introducing impurities of a first conduction type into a drain-layer formation region; 
 amorphizing single crystals of the semiconductor substrate in a source-layer formation region by introducing inert impurities into the source-layer formation region; 
 introducing impurities of a second conduction type into the source-layer formation region; and 
 bringing at least an amorphous semiconductor in the source-layer formation region into a single crystal semiconductor and activating the impurities of the second conduction type in the source-layer formation region by irradiating the semiconductor substrate with microwaves. 
 
     
     
       2. The method of  claim 1 , further comprising activating the impurities of the first conduction type in the drain-layer formation region by performing heat treatment after introducing the impurities of the first conduction type into the drain-layer formation region, wherein
 the single crystals of the semiconductor substrate in the source-layer formation region are amorphized after activating the impurities of the first conduction type in the drain-layer formation region. 
 
     
     
       3. The method of  claim 1 , wherein the impurities of the first conduction type in the drain-layer formation region are deeper than the impurities of the second conduction type in the source-layer formation region. 
     
     
       4. The method of  claim 2 , wherein the impurities of the first conduction type in the drain-layer formation region are deeper than the impurities of the second conduction type in the source-layer formation region. 
     
     
       5. The method of  claim 1 , wherein the inert impurities are germanium, silicon, or a germanium-silicon compound (Si 1-x Ge x  (where X=0 to 1)). 
     
     
       6. The method of  claim 2 , wherein the inert impurities are germanium, silicon, or a germanium-silicon compound (Si 1-x Ge x  (where X=0 to 1)). 
     
     
       7. The method of  claim 3 , wherein the inert impurities are germanium, silicon, or a germanium-silicon compound (Si 1-x Ge x  (where X=0 to 1)). 
     
     
       8. The method of  claim 1 , wherein the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region. 
     
     
       9. The method of  claim 2 , wherein the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region. 
     
     
       10. The method of  claim 3 , wherein the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region. 
     
     
       11. The method of  claim 1 , wherein
 the single crystals of the semiconductor substrate in the drain-layer formation region are amorphized by introducing the inert impurities into the drain-layer formation region before introducing the impurities of the first conduction type into the drain-layer formation region, and 
 the amorphous semiconductor in the source-layer formation region and an amorphous semiconductor in the drain-layer formation region are brought into single crystal semiconductors, and the impurities of the first conduction type in the drain-layer formation region and the impurities of the second conduction type in the source-layer formation region are activated, when the semiconductor substrate is irradiated with the microwaves. 
 
     
     
       12. The method of  claim 11 , wherein the inert impurities are introduced deeper in the source-layer formation region than in the drain-layer formation region. 
     
     
       13. The method of  claim 11 , wherein the drain-layer formation region is amorphized by implantation of the inert impurities more deeply than the source-layer formation region. 
     
     
       14. The method of  claim 12 , wherein the drain-layer formation region is amorphized by implantation, of the inert impurities more deeply than the source-layer formation region. 
     
     
       15. The method of Claim:  11 , wherein: the inert impurities include germanium, silicon, or a germanium-silicon compound (Si 1-x Ge x (where X=0 to 1)). 
     
     
       16. The method of  claim 11 , wherein
 the inert Impurities are introduced deeper than the impurities of the first conduction type in the drain-layer formation region, and 
 the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region. 
 
     
     
       17. The method of  claim 12 , wherein
 the inert impurities are introduced deeper than the impurities of the first conduction type in the drain-layer formation region, and 
 the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region. 
 
     
     
       18. The method of  claim 13 , wherein
 the inert impurities are introduced deeper than the impurities of the first conduction type in the drain-layer formation region, and 
 the inert impurities are introduced deeper than the impurities of the second conduction type in the source-layer formation region.